Twister and trimmer head for spring assembly machines



Sept. 6, 1960 WYNKOQP 2,951,512

TWISTER AND TRIMMER HEAD FOR SPRING ASSEMBLY MACHINES Filed June 25, 1956 v 2 Sheets-Sheet 1 Fig. 7

r Fig.

IN VEN TOR.

t BY Francis Y.W 00p.

ATTORNEY.

Sept. 6, 1960 F, WYNKOOP 2,951,512

TWISTER AND TRIMMER HEAD FOR SPRING ASSEMBLY MACHINES Filed June 25. 1956 2 Sheets-Sheet 2 Fig. 4

INVENTOR.

Francis Y. Wynkoop.

ATTORNEY United Sttes Patent TWISTER AND TRIMMER HEAD FOR SPRING ASSEMBLY MACHINES Francis Y. Wynkoop, 1205 S. LincoluSL, Denver, Colo.

Filed June 25, 1956, Ser. No. 593,726

'6 Claims. (Cl. 140-103) This invention relates to the art and practice of producing coil spring assembly units such as are extensively utilized as bed springs, as essential components of box springs and innerspring mattresses, and the like, and more particularly to the conventional interlacing operation automatically and repetitiously applied in such production to unite adjacent rows of initially-separate coil springs by means of helicals, or pigtails, and has as an object to provide novel and improved means efiective to trim, close and finish the ends of such helicals in automatic reaction to completion of interlacing operations accomplished thereby.

A further object of the invention is to provide novel and improved means susceptible of operative association with conventional spring assembly machines to trim, close and finish the ends of helical lacing elements in automatic reaction to placement thereof by the associated machine.

A further object of the invention is to provide a novel and improved twister head operable as an attachment to conventional spring assembly machines to automatically trim, close and finish the ends of helical lacing elements applied by such machines in reaction to completion of the lacing operation accomplished thereby.

A further object of the invention is to provide a nove and improved twister head operable to automatically trim, close and finish the ends of helical lacing elements applied by conventional spring assembly machines that is relatively simple and inexpensive of construction and operative installation, adaptable to operative association with spring assembly and other machines of diverse make and structural particularity, that is positive and etficient inoperation, durable in use, and completely devoid of effect upon or interference with the functions and operations of the machine Wherewith it is associated.

With the foregoing and other objects in view, my invention consists in the construction, arrangement, and operative combination of elements as hereinafter described, pointed out in my claims, and illustrated by the accompanying drawings, in which Figure 1 is a fragmentary, somewhat diagrammatic front end elevation of a conventional spring assembly machine as typically and operativcly associated with twister and trimmer heads of the invention in an arrangement of the latter effective to close and finish both ends of both helicals applied by the machine to interlock the upper and lower end coils of a double row of spring elements, an intermediate portion of the machine not essential to an understanding of the invention being broken away to conserve space.

Figure 2 is a fragmentary plan view, partially in section, of the organization according to Figure 1 taken substantially on the indicated line 2-2 of said latter view.

Figure 3 is a top plan View, on a relatively-enlarged scale, of the twister head organization and mounting shown at the left-hand end of Figure 2.

Figure 4 is a longitudinal section through, and on a somewhat reduced scale relative to, the twister head of Figure 3 taken substantially on the indicated line 4-4 of said latter view with movable elements of the head at one limit of their range of actuation.

Figure 5 is a sectional view of the upper portion of the arrangement according to Figure 4 with upper end elements of the latter view removed and the movable elements of the head at the limit of their travel range opposite to that represented by Figure 4.

Figure 6 is a plan view, on the same scale as Figure 3, of the upper end of the arrangement according to Figure 5.

Figure 7 is a fragmentary detail elevation of the upper end of the twister head on the same scale as and as viewed from the direction of the arrow A in Figure 3.

Figure 8 is a vertical section longitudinally through a typical switch unit employed with certain twister heads of the invention.

Figure 9 is a vertical section through a typical electrically-actuable valve for the control of fluid pressure flow with respect to each of the twister heads of the invention.

Figure 10 is an elevation, on a relatively enlarged scale, of an end portion of a conventional helical lacing element as typically closed and finished by the twister heads of the invention.

Figure 11 is an elevation of the end portion of the lacing element shown in Figure 10 as represented on a plane perpendicular to that of said latter view.

Figure 12 is a top plan view, on a relatively enlarged scale, of the trimming cutter arrangement represented at the right-hand end of Figure 2.

Figure 13 is an end elevation of the organization according to Figure 12.

The assembly of a plurality of like coil spring elements in and to form a flat, generally rectangular unit of desiredsize has become an extensive industrial practice utilizing machines of largely automatic type. In some diversity of structure, conventional spring assembly machines of wide popularity are arranged to support a double row of double-cone spring elements with the axes of the spring elements of each row in a common plane parallel to that containing the axes of the elements in the adjacent row and with the base coils at each end of each of said elements tangentially registered with, or overlapped upon, the corresponding base coils of the elements of the adjacent row, and to interlace the soregistered, or overlapped, arcs of the base coils by means of a stiif wire helix, known as a helical or igtail, rotated about its axis and simultaneously axially advanced by the machine along the line common to the contact or overlap of the base coils. It is usual practice to utilize preformed helicals pre-cut to a length sufficient to engage all of the registered or overlapped base coil arcs at either side of the double row assembly of spring elements with some excess manifest upon completion of the operation as a short extension outwardly from the base coil arcs thereby engaged at each end of the double row, and feed of the helical in a spiral advance appropriate to threadedly wind the same over and about the registered or overlapped base coil arcs is customarily had by means of a succession. of feed roll units spaced along the travel path of the helical. Variations of spring assembly practice include the feeding of a continuous helical, or helicals precut to lengths greater than that desired for the finished lacing, through rolls at but one side of the machine with consequent necessity for a cutting or trimming operation on the trailing end of the placed helical. Spring assembly machines operable as above briefly set forth are practical and efiicient to effect interlacing of successive rows of spring elements to completion of a unit of desired length, but since the helicals applied by the machine are left as inserted with open ends projecting at each side of the double row thereby interlaced, one of which may require trimming to length, which open ends are characterized by a spirally-directed free end of the helical Wire constituting a snagging menace and impose no limitation upon possible spiral shift of the helical in either direction, it has been heretofore necessary to trim' and then manually close and finish the. ends of the helicals, as by twisting of the terminal loops of the helical through the agency of pliers, or the like, in a tedious and expensive manner uncertain as to uniformity of result. Hence, to advantageously supplement the performance of known and conventional'spring assembly machines with elimination of occasion for the manual finish operation above mentioned, the instant invention is directed to themevision of twister heads adapted for attachment to'and operative association with such machines where they func tion in automatic reaction to completion of each lacing operation accomplished by means of a helical to immediatelytwist the terminal arc or loop at each end of the helical and to thereby close and finish said ends, and, where requisite, to simultaneously trim away excess helical length.

In the construction and operative organization of the improvement illustrated by the drawings, a conventional springassembly machine is typified by the representation of a rigid transverse frame member suitably supported, as by means of legs 11, in a horizontal disposition subjacent and parallel to a complementary frame member 12 fixedly correlated therewith by means of struts 13, or otherwise. The frame members 10 and 12 carry die blocks (not shown) actuable to grip the opposite end coils of separate, like coil springs 14 in such manner as to assemble and hold the same as a double row thereof between the frame members with adjacent arcs of the end coils of the springs tangent or slightly overlapped in an alignment parallel to the contiguous frame member. In addition to the die blocks, the frame members 10 and 12 operatively mount feed roll units (not shown) powered in an arrangement effective to frictionally engage with convolutions of a straight, stiff-wire helical, or pigtail, 15 which may be pre-cut to finish length or characterized by excess length 15' and to axially advance the same with a spiral rotation about its axis from one end to the other end of the double row of springs 14 along the path of end coil tangency or overlap characterizing the upper and lower sides of the spring assembly determined by the die blocks, thus to spirally thread the helical with secure interlacing eifect through the double row of springs, at both the upper and lower ends thereof, and about the tangent or overlapped arcs of the end coils of the springs paired laterally of the double row assembly. The foregoing is but representative of the organization and operation of conventional spring assembly machines wherewith the improvements of the instant invention are susceptible of advantageous correlation, and since such conventional machines provide occasion for and in and of themselves form no part of the present invention, it is apparent that but general graphic and descriptive reference thereto should suffice to establish the environment and operative locus of the improvements hereinafter set forth.

Adapated for fixed attachment to the frame members 10 and 12, or analogous elements, of a conventional spring assembly machine in operative correlation with each end of each helical 15 applied with interlacing effect by the machine as hereinbelow described, the twister head of the invention is a unique combination of cooperating elements unitarily correlated for interaction through mounted association with a rigid, elongated member 16, such as a length of angle iron, appropriate for fixed attachment to frame members of the spring assembly machine whereto the improvement is to be applied. Inwardly adjacent one end of the member 16, an openend sleeve 17, angular in cross section, is securely fixed thereto as a slide bearing in longitudinal alignment with h member, n a ho lsw Pl e 18 slid bly an 2 rotatably engages within said sleeve 17 for free rectilinear reciprocation relative thereto. The sleeve 17 is much shorter than the member 16 and is related with the latter to dispose one of the sleeve ends at a moderate spacing inwardly from the adjacent end of the member, which end of the sleeve is closed by a plate 19 fixed thereto transversely of the sleeve. The plate 19 is formed with a circular aperture substantially centrally thereof which opens to the interior of the sleeve 17 through an annular flange 20 directed inwardly of said sleeve for the rotatable accommodation of a cylindrical boss 21 coaxially outstanding from one end of a cylindrical block 22 thereby mounted for free rotation exteriorly adjacent the plate 19 with the free end of said boss 21 interiorly of the sleeve 17. The block 22 is coaxially socketed through its face remote from the boss 21 for the reception of one end of a stem 23 detachably secured thereto by a pin 24 diametrically of the block and stem normally retained in its position of use by a snap ring 25 circum' ferentially of the block, and a web 26 fixed to the member 16 in spaced parallelism with the plate 19 is apertured and bushed to provide a journal bearing through which the stem 23 extends axially of the block 22 and away from the sleeve 17 to terminate in a free end projecting beyond the adjacent end of the associated member,

The free end of the boss 21 within the sleeve 17 is formedv with a diametric notch opening axially thereof for the reception of one end of a spirally-twisted, flat strip 27 pinned, as at 28, within the notch to extend from said boss and substantially centrally of the sleeve in a direction opposite to that of the stem 23 projection. The end of the plunger 18 opposed to the boss 21 is preferably formed with a tubular collar 29 loosely accommodative of the strip 27 and closed at its end adjacent said boss by a plate 30 intersected by a diametric slot conformed to slidably receive said strip, whereby to reflect reciprocation of the plunger in the sleeve 17 with the strip 27 engaged through said slot as rotation of the strip and the elements to which the strip is attached. The strip 27 may be dimensioned and twisted to provide rotational effect of desired extent, but for association with a spring assembly machine it is preferably twisted through substantially one-half of a full turn in a length spanning between attachment to the boss 21 and engagement through the slot of the plate 30 when the plunger is at the limit of its separation from said boss, thus to provide for rotation of the block 22 and associated stem 23 through an angle on the order of one hundred and eighty degrees at each shift of the plunger through its full range of travel within the sleeve.

Power is applied to the plunger 18 for shift thereof in the sleeve 17 and toward the boss 21 through the agency of a pneumatic ram 31, of conventional cylinder and piston type, secured to the member 16 spacedly adjacent the open end of said sleeve with its extensible piston rod element 32 directed toward and in coaxial alignment with the stem 23 in such engagement against the end of the plunger remote from said stem as to position the plunger at the limit of its travel away from the boss 21 when the said ram is fully retracted, and an expana sive coil spring 33 acts within the sleeve 17 between the plate 19 and inner end of the plunger to yieldably retain the latter engaged with the end of the piston rod element 32 and to return the plunger toward the ram when and as the latter is retracted. Connected to a source or supply of pneumatic pressure through a line 34, the ram 31 operates in an obvious manner to effect rotation of the stem 23 about its axis in the mounting described. Extension of the ram piston rod element 32 in reaction to input of pressure through the line 34 correspondingly shifts the plunger 18 in the sleeve 17 and toward the boss 21, with consequent and proportional rotationof the twisted strip 27, and the boss, block, and stem elements therewith associated, as said strip slidably traverses the slot in the. end plate 3.9 of the non-rotatable plunger,

and release of pressure from the ram occasions retraction of the piston rod element 32 and permits-the spring 33 to effect return shift of the plunger with concomitant reverse rotation of the strip, boss, block and stem. Inasmuch as the pressure of the ram 31 is applied with an effect tending to urge the block 22 against the web 26, a thrust washer 35, or equivalent friction-minimizing facility, is expediently interposed between the otherwise coacting faces of said block and web.

Rotation of the stem 23 of the twister head unit in reaction to thrust of the associated ram is applied to terminal convolutions of the helicals placed by the spring assembly machine to close and finish the ends of such helicals, for which purpose the free end of the stem is formed with a diametric, axially-opening notch 36 through which the convolutions of the helical 15 may freely travel in a considerable depth of engagement during spiral travel of the helical about and along its axis. Promotive of operating economy and facilitative of maintenance, the opposite ends of the stem 23 may be identically formed with notches 36 and holes for the accommodation of the pin 24, whereby to condition the stem for inversion in its mounting and continued use whenever the etfectiveness of the working end of the stem becomes impaired through wear or damage.

Operative correlation of the twister head units constructed and organized as shown and described with a conventional spring assembly machine arranged to apply preformed helicals for the interlacing of coil springs is had through attachment of one of the head units to fixed frame elements of the machine at each end of each of the helicals as placed by the machine and in such disposition as to approach the free end of each head stem 23 closely to the axis of the associated placed helical with the axis of the stem substantially radial of the helical axis. As indicated by Figure 1, wherein the upper arrangement is adapted for coaction with helicals pre-cut to finished length and the lower arrangement is adapted for coaction with longer, or continuous helicals, it is practical and expedient to attach a twister head unit to and at each end of the frame member with their stems 23 directed upwardly in the specified correlation with ends of the lower helical placed by the machine, and to attach a twister head unit to and at each end of the frame member 12 with the stems 23 of the latter directed downwardly in the specified correlation with ends of the upper helical placed by the machine, whereby to dispose the members 16 of the said units substantially vertical and out of interfering relation with the customary manipulations pertinent to operation of the machine. Variations of assembly machine frame construction and arrangement will determine to some extent the precise manner of attaching the twister head units to a given frame in appropriate operative correlation with the helicals placed by the machine, but the rigid, elongated member 16 characterizing each of the heads facilitates attachment of the units by means of bolts, welding, the use of clips and adapters, special fittings, and the like, all of which are known and available for use within the ordinary skill of the art. Whatever may prove to be the feasible mode of attachment of the twister head units to a given assembly machine, they are securely aflixed to the machine in the general arrangement and operative correlation with the helicals placed by the machine typified by the views of i the drawings and above particularized. Impelled, guided, and controlled by the feed roll units of the machine, each helical placed by the machine follows a definite, predetermined path identical with that traversed by any other helical fed through the same set of feed roll units, thus making it feasible to set the stems 23 of the twister heads in such angular adjustment as to align their notches 36 for reception of the convolutions of the helical with which they are designed to coact, for which purpose a stud 37 at and fixedly projecting radially from the midlength of the stem 23 is arranged to function as a stop determinative of the inoperative angular disposition of the associated stem 23 and limitative of stem angular displacement through engagement with the inner end of one or the other of a pair of rods 38 threadedly and adjustably instanding through the member 16 at opposite sides of the said stem in the plane through which the stud 37 oscillates as the stem is rotated. Thus, through adjustment of the appropriate one of the rods 38, the stem 23 of each of the twister heads associated with a spring assembly machine may be positioned in its inoperative relation typified by retraction of the associated ram 31 to align the stem notch 36' with the spiral travel path of the helical wherewith the stem is designed to coact, whereby to provide, in correlation with each helical placed by the machine, a twister head stem 23 engaged by means of its notch 36 with the leading terminal convolution of the related helical upon completion of the interlacing operation to which the helical is applied by the machine. Obviously, the leading end of the helical is infed to the machine with a spiralling travel through the notch '36 of the stem 23 at the side of the machine from which the helical is first entered and the full length of the finished helical travels through said notch during the interlacing operation to leave in engagement with said notch the convolution which terminates the trailing end of the finished helical when the terminal convolution at the leading end of the helical engages with the notch '36 of the stem 23 .on the other side of the machine as the interlacing operation is completed.

Attached to and correlated with a spring assembly machine to establish engagement of the terminal convolutions of the finished helicals placed by the machine within the notches 36 of the stems 23 as an automatic reaction to the placing of the helicals by the machine, the twister heads operate through rotation of their stems 23 consequent upon actuation of their respective rams '31 to close and finish the ends of the helicals, and to trim away excess helical length, with a twisting action applied by said stems to the terminal con'volutions thereby engaged to an angular extent determined by engagement of the stud 37 with the end of the adjustable rod 38 other than that against which stud sests when the ram is retracted. Actuation of he rams .31 of the complemenary twister heads associaed with each helical is an automatic, simultaneous operation trigger-ed by-the leading end of the helical at the ends of its interlacing travel. For regulable, automatic control of input of pneumatic pressure to the rams 31, the line 34 serving each of said rams connects with the source or supply of pneumatic pressure, represented by the line 34' (Figure 9), through an electrically-actuable valve of any suitable type and construction shiftable between a position effective to establish flow communication between the lines 34 and 34' and an alternative position effective to establish communication of the line '34 with atmosphere while interrupting flow from the line 34, in the manner typified by the valve arrangement of Figure 9. As illustrated, the valve organization comprises a valve body 39 defining a chamber reciprocably housing a valve block 40 fixedly mounting a post 41 slidably associated with and to function as the armature of a solenoid 42 carried by the body, and a spring 43 yieldably urging the block 40 to the limit of its travel within the body 39 away from said solenoid.

.The lines 34 and 34' connect through opposite side walls of the body 39 against which theblock 40 is adapted. to slide and a port 44 intersects the side of said body to which the line 34 connects between said line and the end of the block 40 adjacent the solenoid 42, and the block 40 is formed with a transverse passage 45 disposed to establish flow communication between the line 34 and said port 44 when the block is at the limit of its travel away from the solenoid 42 and with a second transverse passage 46 disposed to establish flow communication between the lines 34and 34' when said block isshifted against the pressure of the spring 43 to the limit of its travelitoward said solenoid. Connected by means of the line 34 with a ram 31 and by means of the line 34' with a source or supply of pneumatic pressure, as represented and above described, the valve is effective through the influence of the spring 43 holding the block 4 3 away from the solenoid 42 to maintain the line 34 in cornmunication with atmosphere through the passage 45 and port 44 for consequent retraction of the associated ram 31 during periods when the solenoid 42 is deenergized. When a circuit 47 serving the solenoid is closed, the post 41 is shifted against the pressure of the spring 43 to move the valve block 40 into closing relation across the port 44 and registration of the passage 45 in connecting relation between the lines 34 and 34 for consequent actuation of the associated ram 31 and rotation of the stem 23 reactive thereto.

The circuits 47 serving the solenoids 42 of the flow control valves associated with and for the independent regulation of pressure flow to the twister head units at the opposite ends of a given helical placed by the spring assembly machine are connected, preferably in parallel, in a common powered circuit including a switch 43 correlated with the twister head unit operable to close and finish the leading end of the helical, to the end that closing of said switch shall simultaneously energize both solenoids for actuation of the two twister heads engaged by the ends of the helical. The switch 48 may be of any expedient type and construction characterized by a normal open-circuit condition which is shiftable to closedcircuit condition in reaction to short travel of a member spring-biased for return to open-circuit condition of the switch, such as a snap-action microswitch or any functional equivalent of the arrangement exemplified by Figure 8. As illustrated, a conventional mercury tube switch element 49 is connected in series with the circuits 47 and is mounted within a housing 56 to normally lie in open relation with the associated circuits and to rock through a vertical are into closing relation with said circuits, with automatic return to open-circuit condition, in reaction to depression of a member 51 spring-biased to project above the top of the housing 50 in axially-reciprocable relation with the housing. The switch 4-8 is attached by means of the housing 50 in any practical manner to the twister head unit engageable by the leading end of the helical in such correlation with the twister head as to mount the switch member 51 with its axis spacedly paralleling that of the twister head stem 23, the free outer end of said member in substantially the same horizontal plane as that of the stem free end, and in offset relation, laterally and outwardly relative to the terminal position of the helical leading end, from said stem at the side of the latter toward which the leading end of the helical spirals upwardly as it travels into engagement with the end notch 36 of the stem. Thus mounted, the switch 45 is yieldably maintained in open-circuit condition during placing of the helical engageable with the twister heads reactive to closing of the switch The switch 48 is automatically closed by the leading end of the helical as the latter spirals upwardly through and in engagement within the notch 36 of the stem 23 adjacent the switch. Such closing of the switch is the function of a hardened plate 52 rockably mounted to span between said stem and the switch member 51 and to normally lie in a plane slightly spaced from and parallel to that common to the free ends of said stem and member. Mounting of the plate 52 in its operative relation with the stem 23 and member 51 is expediently had through the use of a block 53 fixed to and laterally across the end of the head unit member 16 in journalling relation with the stem 23 extending therethrough, which block may also serve for attachment of the member to frame elements of the machine, a bracket 54 fixedly related wtih said block in spaced parallelism with the free end of the adjacent stern- 23 presenting a side surface parallel to and offset laterally from the plate 52 position, a bolt 55 through said bracket perpendicular to and projecting beyond said side surface thereof and hence transversely of the plate 52 position, a clip 56 rockably carried by said bolt above the block 53, and means, including a clamp fitting 52', for detachably and adjustably engaging the plate 52 with said clip. Secured and braced in the clip 56 by means of the fitting 52 and rockable therewith about thhe axis of the bolt 55, the plate 52 at one end overlies and engages with the free end of the switch member 51 and is yieldably held thereby at one limit of its range of oscillation, while at its other end said plate over-lies the end of the stem 23 closely adjacent or in possible engagement therewith. The end of the plate 52 coacting with the stem 23 is worked to the form of a lip 57 angularly terminating said plate as an edge substantially parallel to the axis of the helical travel path and overlapping inwardly across the free end of the stem 23 toward said axis to cover slightly less than one-half of the stem end area, whereby, as the leading end of the helical spirals inwardly through and outwardly from the notch 36 of the stem in the final phase of its placement by the machine, said end engages the surface of the hardened plate 52 opposed to the stern adjacent the lip 57, lifts thereagainst to rock the plate on the axis of the bolt 55 with consequent depression of the switch member 51, closing of the switch 48, and termination of helical travel. Closing of the switch by the advancing end of the helical as the latter engages the stem in the final phase of its travel operates the pressure flow control valves and actuates the rams of the twister head units at both ends of the helical, thereby effecting rotation of the stems 23 for angular crimping, and consequent closing and finishing, of the convolutions terminating both ends of the helical 15 pre-cut to finished length as represented by the upper arrangement of Figure 1. The twisting operation performed by the stems 23 on the ends of the helicals frees the same from the adjacent ends of the plates 52 while the die blocks open for ejection of the interlaced coil springs 14, in which relation of the machine and twister head elements the flow control valves return to cut off fiow of pressure to the rams and to condition the latter for retraction and an automatic resetting of the twister head units and their elements for repetitious operation upon the infeed thereto of a subsequent helical.

As represented in the lower arrangement of Figure 1 and in Figure 2, the characteristic action of the stem 23 at the side of the machine to which the helical is infed may be utilized for trimming the placed helical to finished length when continuous, or overlcngth, helical material is employed. When the placed helical 15 carries excess length 15' trailing the stem 23 at the infeed side of the machine, it is obvious that an arc of the convolution engaged in the slot 36 of said stem will arch upwardly over the upper end of the stem to spiral away from the machine, so that a severing of said are at the plane of the stem 23 upper end operates to trim away excess helical length while retaining a bight of the terminal convolution at the trailing end of the helical within the notch 36 subject to the twisting action of the stern. Such trimming of the overlength helical is conveniently and automatically accomplished by means of a shear knife 58, of appropriate tool material, fixed, as by means of a holder 59 secured to rigid elements of the associated twister head or machine frame, to extend generally diametrically of and closely adjacent the upper end plane of the stem 23 along the side of the stem slot 36 closest to the machine frame. Positioned as shown and described, the knife 58 engages freely between the upper arcs of adjacent helical convolutions and in no way interferes with infced of the helical through the stem slot, but when the associated twister head is actuated to rotate its stem 23 under the knife, the arc of the helical convolution upstanding from the slot 36 is pinched between said knife and the side of the rotating slot and thereby trimmed away from the placed helical as the terminal convolution of the latter is closed and finished as above set forth.

While the twister heads of the invention have been shown and described in operative association with a spring assembly machine, where they are of manifest practical advantage, it is of course fully apparent that they are, expediently adaptable for analogous use in association with various types and constructions of machines and apparatus where rotational reaction to linearly-applied power may prove to be advantageous.

Since changes, variations, and modifications in the form, construction, and arrangement of the elements shown and described may be had without departing from the spirit of my invention, I wish to be understood as being limited solely by the scope of the appended claims, rather than by any details of the illustrative showing and foregoing description. 7 r

'I claim as my invention:

1. The combination with a spring assembly machine operable to spirally advance and position a stiff wire helicalin interlacing relation with juxtaposed base coil arcs of-a double-row of coil spring elements, of a twister head unit afiixed to said machine for registration with each end of a helical placed thereby, a stem rotatable independently of and free from connection with the operating organization of the machine in each said unit about an axis substantially perpendicular to the path of helical travel disposed with a free end spacedly adjacent the helical travel path axis, a notch diametrically of each stem free end engageable by terminal convolutions of the associated helical as an incident of helical placement by the machine disposed in rest position of said stem at the inoperative limit of its rotational range to receive feed of the helical thereinto, means for the independent rotation of each said stem, and means independent of the operating organization of the machine directly reactive solely to final positioning advance of the helical for simultaneous actuation of said first means, whereinthe means for independent rotation of the stems comprises a twisted strip aflixed to and extending from the end of the stern remote from the notch, a plunger non-rotatably reoiprocable on a path longitudinally aligned with said stem in slidable coaction with said strip, whereby shift of said plunger is reflected as rotation of the stem, a spring yieldably urging said plunger away from said stem to a limiting position effective to present the stem notch for infeed of the helical thereto, and a pneumatic ram selectively extensible in engagement with said plunger to move the latter toward the stem against the pressure of said spring for consequent angular displacement of said notch about the stern axis.

2. The combination with a spring assembly machine operable to spirally advance and position a stifl wire helical in interlacing relation with juxtaposed base coil arcs of a double row of coil spring elements, of a twister head unit afiixed to said machine for registration with each end of a helical placed thereby, a stem rotatable independently of and free from connection with the operating organization of the machine in each said unit about an axis substantially perpendicular to the path of helical travel disposed with a free end spacedly adjacent the helical travel path axis, a notch diametrically of each stern free end engageable by terminal convolutions of the associated helical as an incident of helical placement by the machine disposed in rest position of said stem at the inoperative limit of its rotational range to receive feed of the helical thereinto, means for the independent rotation of each said stem, and means independent of the operating organization of the machine directly reactive solely to final positioning advance of the helical for simultaneons actuation of said first means, wherein the means for independent rotation of the stems comprises a twisted strip aflixed to and extending from the end of the stem remote from the notch, a plunger non-rotatably reciprocable on a path longitudinally aligned with said stem in slidable coaction with said strip, whereby shift of said plunger is reflected as rotation of the stem, a spring yieldably urging said plunger away from said stem to a limiting position effective to present the stem notch [for infeed of the helical thereto, a pneumatic ram selectively extensible in engagement with said plunger to move the latter toward the stem against the pressure of said spring for consequent angular displacement of said notch about the stem axis, a pressure flow line serving said ram, a valve. in said line normally inhibiting pressure flow to the ram while venting the latter to atmosphere and actuable to establish pressure flow to the ram with interruption of the vent communication to atmosphere, electrically-responsive means in actuating association with said valve, and a switch-controlled circuit serving said electrically-responsive means.

3. The combination with a spring assembly machine operable to spirally advance and position a stiif wire helical in interlacing relation with juxtaposed base coil arcs of a double row of coil spring elements, of a twister head unit afiixed to said machine for registration with each end of a helical placed thereby, a stem rotatable independently of and free from connection with the operating organization of the machine in each said unit about an 'axis substantially perpendicular to the path of helical travel disposed with a free end spacedlly adjacent the helical travel path axis, a notch diametrically of each stem free end engageable by terminal convolutions of the associated helical as an incident of helical placement by the machine disposed in rest position of said stem at the inoperative limit of its rotational range to receive feed of the helical thereinto, means for the independent rotation of each said stem, and means independent of the operating organization of the machine directly reactive solelyto final positioning advance of the helical for simultaneous actuation of said first means, wherein the means for independent rotation of the stems includes a pneumatic ram spring-biased to retracted condition operatively associated with and selectively extensible to rotate each of the stems from a position presenting the associated notch to receive infeed of the helical to relative angular displacement of the notch, a pressure flow line serving the ram, and a valve in the line serving each ram normally inhibiting pressure flow to the ram while venting the latter to atmosphere and electrically actuable to establish pressure flow to the ram with interruption of the vent communication to atmosphere, and the means for simultaneous actuation of the stem-rotating means in automatic reaction to final positioning advance of the helical comprises electrically-responsive means for shifting each said valve for pressure supply to the associated ram, a circuit common to said electrically-responsive means of the separate valves, a normally-open switch in said circuit adjacent the stem finally engageable by the leading end of the helical, and a plate tiltable to close said switch disposed for switch-closing reaction to the leading end of the helical as the latter spirals through the notch of said stem.

4. A twister head attachment, comprising a rigid, elongated, attaching member, a stem carried by said member for rotation about its axis longitudinal of the member and projecting at one end beyond the member, a notch diametrically of the free end of said stem traversable of the material to be twisted, means for adjustably determining the angular disposition of said notch and for limiting angular displacement of said stem to a disposition at the inoperative limit of its rotational range accommodating infeed of the material to be twisted into the associated notch laterally of the stem, a slide bearing longitudinally of said member aligned with the axis of said stem, a plunger non-rotatably reciprocable in said slide bearing, a spring yieldably urging said plunger away from the stem, a twisted strip aflixed to and extending from the end of said stem adjacent the plunger in slidable coaction through the end of the latter opposed to the stem, whereby shift of the plunger is reflected as rotation of the stem, a selectively extensible pneumatic ram mounted on said member in axial alignment with said stem and in end engagement of its extensible element with the end of the plunger remote from the stem, a pressure flow line serving said ram, an electricallyactuable valve in said line shiftable between a position accommodating pressure supply to the ram and a position of pressure relief from the ram to atmosphere, and a switch-controlled circuit serving the actuating component of said valve.

5. A twister head attachment, comprising a rigid, elongated, attaching member, a stem carried by said member for rotation about its axis longitudinal of the member and projecting at one end beyond the member, a notch diametrically of the free end of said stern traversable by the material to be twisted, means for adjustably determining the angular disposition of said notch and for limiting angular displacement of said stem to a disposition at the inoperative limit of its rotational range accommodating inf'eed of the material to be twisted into the associated notch laterally of the stem, a slide bearing longitudinally of said member aligned with the axis of said stem, a plunger non-rotatably reciprocable in said slide bearing, a spring yieldably urging said plunger away from the stem, a twisted strip aflixed to and extending from the end of said stem adjacent the plunger in slidable coaction through the end of the latter opposed to the stem, whereby shift of the plunger is reflected as rotation of the stem, a selectively extensible pneumatic ram mounted on said member in axial alignment with said stem and in end engagement of its extensible element with the end of the plunger remote from the stem, a pressure flow line serving said ram, and an electricallyactuable valve in said line shiftable between a position accommodating pressure supply to the ram and a position of pressure relief from the ram to atmosphere; together with a circuit serving said valve, a switch in said circuit adjacent the stem engaged by the leading end of material tion of pressure supply to said ram eflfective through the 7 traversing the stern notch, and means reactive to ad- Vance of such material through the notch of said stem.

to close said switch for actuation of said valve to a posi associated elements to rotate said stem and notch with consequent twisting of material engaged through the latter..

6. A twister and trimmer head attachment, comprising a rigid, elongated, attaching member, a stem carried by said member for rotation about its axis longitudinal of the member and projecting at one end beyond the member, a notch diametrically of the free end of saidv stem traversable by material to be twisted, means for adjustably determining the angular disposition of said notch and for limiting angular displacement of said stem to a disposition at the inoperative limit of its rotational range accommodating infeed of the material to be twisted into the associated notch laterally of the stem, a selectively extensible pneumatic ram mounted on said member, means reactive to said ram and engaged with said stem operable to reflect reciprocation of the ram as rotation of the stem, means responsive to infeed of material through said notch for the automatic actuation of said ram, and a knife fixed to extend across and closely adjacent the free end of said stem for shearing coaction with the stem notch upon rotation of the stem.

References Cited in the file of this patent UNITED STATES PATENTS I L f", 

